Tag Archives: buxus blight

Plants that do not know their place – high maintenance culprits

Dudley on the bridge amidst 'Snow Showers'

Dudley on the bridge amidst ‘Snow Showers’

You will never see me advocating enthusiastically for low maintenance gardening. It is not our style. But I do think some plants need to know their place in life. Some clamour for way more attention than they deserve. We have been thinking about plants that are unjustifiably high maintenance. First to go here were almost all plants that require chemical intervention (spraying) to keep them looking good – or even alive. Goodbye underperforming roses and badly thrip-infested rhododendrons. These might be great in other climates, but here? No. Next in the spotlight are some of the other high maintenance plant options.

Who doesn’t love wisteria? But unless you are willing to give them the attention they require, they are best admired in somebody else’s garden. More than any other plant I can think of, they cannot just be planted and left. Miss a prune and it only takes one season for them to crack the spouting – I know this from experience. They also put out runners that R U N considerable distances. What is more, if you prune them incorrectly, they don’t flower which really defeats the purpose of growing them.

We dug three wisteria out this winter. Two were not flowering well enough to justify keeping them (not enough light, I think). The third was running amok in a wild area and threatening world domination. We have still kept about seven plants, including two on our bridge which are great performers but I am meticulous about pruning them both in summer and winter. Even so, they can join hands in the middle, trying to block passage through.

Climbing roses are another plant that I personally think are best admired in somebody else’s garden. I once planted ‘Albertine’ over an arch in the vegetable garden. It looked lovely in flower but then it produced many long whips covered in fierce thorns. Not only were they waving away waiting to ensnare anyone who walked down the path, pruning was a Major Mission. When it took me the better part of a day to prune it and tie it in, I decided that the rewards did not justify the effort. The advice often seen in English media about letting climbing roses scramble through trees and not worrying about pruning them at all does not translate to our gardening conditions. Any rose that strong is more likely to collapse the host tree, or swamp it at least. We are trialling some semi-thornless pillar roses but rampant, thorny climbers – no thanks.

magnolia-little-gemAny potentially large tree planted in the wrong place is going to be high maintenance. Vegetable time bombs, we call them. I see it with Magnolia grandiflora “Little Gem” in urban gardens more than any other plant I can think of. Aforementioned “Little Gem” is only little by comparison with something that might equally be called “Extremely Giant Gem”. It is not a dwarf tree. Plant it in a confined space – I know of a twin row of five or six aside lining a very narrow driveway in town – and it will either be high maintenance on an ongoing basis to keep it confined or an expensive removal job when it becomes a major problem.

Clipped hedges can give great definition in a garden – green walls, really. But I rate any hedge that needs trimming more than once or twice a year as high maintenance. While some people are quite happy to trim hedges frequently to keep sharp-edged definition, I see that activity as being like vacuuming the house. There is nothing creative about such a repetitious activity. To me, hedges are   utility tools, a background, not the centre of attention so they shouldn’t be demanding as much or more attention as the foreground stars of the garden. I would not plant any in teucrium or lonicera for these reasons.

A blight upon your buxus!

A blight upon your buxus!

Buxus used to be infinitely useful and undemanding hedging plant. But with the advent of buxus blight in many areas, that status has changed. I know of gardeners who are spraying their buxus hedges every few weeks, just to keep them leafy and to hold blight at bay. Woah there! Aside from environmental considerations (even if it is just a copper spray, the long term use of that is not good), it turns a handy, low maintenance plant into a high maintenance option.

Camellia Fairy Blush

Camellia Fairy Blush

Give me our small leafed camellia hedges any day. A hard prune in early spring followed by a light tidy-up in autumn is all they need. Also they light up a winter’s day while feeding the birds and over-wintering monarch butterflies. Camellias ‘Fairy Blush’, transnokoensis and microphylla are our preferred options.

We can and do fuss over some plants but utility plants? No. They need to know their place in life and that means not being so demanding.

First published in the September issue of NZ Gardener and reprinted here with their permission. 



Garden lore

[My garden] is a confusion of kitchen and parterre, orchard and flower garden, which lie so mixt and interwoven with one another, that if a foreigner, who had seen nothing of our country, should be conveyed into my garden at his first landing, he would look upon it as a natural wilderness, and one of the uncultivated parts of our country.

Joseph Addison, The Tatler (1710)

The dreaded buxus blight - but not in our garden

The dreaded buxus blight – but not in our garden

Buxus blight
Judging by all the search engine terms I see leading people to my website (www.jury.co.nz), buxus blight is currently running rampant. In summary, if your buxus has turned brown all over, it is dead. If it has big dead patches and some green left, odds on you have buxus blight. All species of buxus get it but it is worst on the most common ones we use here – B. sempervirens and var. suffriticosa. It is a fungus – cylindrocladium – and it is a problem throughout the world where buxus is grown. Being a fungus means that it is spread by spore and these light little packages of blight can be spread by wind.

You can treat buxus blight but you can’t cure it. As soon as you stop treating it, the dead patches will start again. Untreated, you are likely to lose the lot eventually and it will look most unattractive in the process. I know of people who are keeping it at bay by using copper sprays and there will be fungicides that will knock it on the head for a while. The trouble is that the repeated use of copper sprays is not good for the environment (eventually you can get a build up that kills earthworms) and fungicides are not the nicest of sprays. It is unlikely that natural sprays using baking soda are of sufficient strength to be effective.

In the end, the decision really is whether you are willing to spray your buxus from here to eternity. Be grateful if you do not have the blight.

First published in the Waikato Times and reprinted here with their permission.


Fortunately not our garden, but it has been pretty discouraging for the friends whose garden it is. Buxus blight on the rampage.

Fortunately not our garden, but it has been pretty discouraging for the friends whose garden it is. Buxus blight on the rampage.

I am not the world’s greatest fan of buxus hedging. But I have some sympathy for the multitude of gardeners who are watching their prized box hedges turn brown. Judging by the Google search terms, it is an alarmingly common problem at the moment. “My buxus has no leaves. Is it dead?” Basically, yes. Buxus is an evergreen plant which never loses all its leaves. “Buxus turning brown.” It is dying. If it is any consolation, Prince Charles is reportedly having the same problem at Highgrove.

The problem is buxus blight – cylindrocladium. It is a fungus so it spreads by spore and it has dispersed extensively across the globe. It is particularly troublesome because it is not affected by temperature – hot or cold, its progress is undeterred, particularly in wet or humid conditions. I have yet to see any information on how far the spore can be carried by wind but it is more likely to be kilometres rather than metres. So unless you are in the country, isolated from other buxus, odds on that your buxus will become infected sooner or later, if it isn’t already. You will know if you have it. The leaves turn brown and fall off and it can spread rapidly. Left to follow its natural course, it is generally terminal.

You can treat buxus blight but you don’t seem to be able to eradicate it. This means you will have to continue treating it for the life of the plants. The best you can hope is to hold it at bay because the spore can survive for a year, maybe two, on the dead leaves and I defy anybody to succeed in removing every single blighted leaf.

A blight upon your buxus

A blight upon your buxus

If you are going to try and salvage your existing buxus, first up you need to thin and clean out the accumulated debris. I am well aware that this is easier said than done, especially when you have a mature hedge which has become so dense you can almost sit on it. A blower vac is pretty much the one only way to go with blasting out the debris, which must then be removed. And thinning is a painstaking task with secateurs. What you are trying to do is to enable the leaves to shed water as quickly as possible and to allow more air movement. These techniques may slow the spread but they won’t treat the existing condition. You will have to spray. It is a fungus, so you need an anti fungal spray. I don’t know of any specific sprays developed to target this condition, but any of the broad spectrum fungicides might work. Anecdotally, I am told that copper works but I am guessing that you have to get it in the early stages for copper and you may have to spray more frequently.

The bottom line is whether you are willing to commit to repeated spraying to save your buxus hedge. For us, the unequivocal answer is no. We just think it is really bad environmental practice. There is evidence that repeated use of copper is not good for the soils. Amongst other things, it kills earth worms which leads to soil compaction and copper residue is cumulative over time. An occasional application is fine, but committing to ongoing spraying is different. Besides, the whole thing about buxus was that it required minimal maintenance – a clip twice a year kept it in shape. Would you choose it knowing that it requires frequent spraying just to keep it alive?

Suffruticosa (the very low growing baby one) appears to be the worst hit, probably because it is the densest grower. Sempervirens is also badly affected and that is by far the most common form around. Be wary of advice that the Asian forms from Japan and Korea don’t get blight. They are Buxus microphylla and microphylla var. koreana or Buxus sinica. Being larger leaved and a little more open in growth, they may shed the water more quickly and be less affected but overseas research says that no buxus species are immune.

It should be pretty obvious at this point that there is no point whatever in taking out affected plants and replacing them with fresh ones of the same variety. The problem is not the individual plants – it is the fungal spores swirling around.

As if the news of buxus blight is not bad enough, there is a further quandary when it comes to a substitute. Put simply, there is no like for like swap. Space does not allow me to look at the alternatives here, but if you want to know more, you will find some options on Buxus Alternatives for Garden Hedges. The bottom line is that there is no other single option which is cheap to buy, grows in sun and shade, has good dark green colour, will re-sprout from bare wood and only requires clipping once or twice a year. Personally, I think it is an opportunity to stand back and rethink garden designs which have leaned far too heavily on defining form by endless box hedging and I will return to this theme in the future.

If you haven’t got buxus blight, be grateful and be vigilant.

(first published in the Waikato Times and reproduced here with their permission)

Buxus alternatives for garden hedges

With buxus blight cutting a swathe through many gardens, it is clear the problem is here to stay. We set out to review some of the alternative plant options. The advantages of box for low hedging include:

• only needs to be trimmed once or possibly twice a year
• has a very small leaf which means that trimming with hedge clippers doesn’t leave unsightly half leaves visible
• good dark green colour
• sprouts from bare wood if trimmed hard
• so easy to root from cutting that it is cheap to buy and easy for the home gardener to propagate more plants
• will also tolerate a certain amount of shade

We have yet to find a proven like-for-like replacement, only plants that fit some of the criteria.

1) Lonicera nitida – ticks all the right boxes bar one, but that is an important one. Good dark colour, tiny leaves, easy to propagate, cheap… but it grows so rapidly that you will have to clip frequently. This may be as much as once a month in the growing season. It will get very twiggy and leggy if you don’t keep it tightly clipped. The same goes for teucrium which needs even more clipping and isn’t even green, though it does make an attractive hedge.

2) Myrtus ugni, usually referred to as the NZ cranberry. Little leaves, easy to strike from cutting, easy to train and can be kept low, delicious fruit but it develops bare patches. It is really only an option for the edible garden area and it won’t make a nice tidy little hedge that resembles buxus. It doesn’t like shade and can be thrip-prone.

Kurume and Gumpo azaleas - there are also white flowered options for those with refined tastes

Kurume and Gumpo azaleas - there are also white flowered options for those with refined tastes

3) Gumpo or Kurume azaleas – these are the small leafed, low growing, evergreen azaleas. Good foliage, clip well, can be kept small though the leaves are larger than buxus and they have excellent shade tolerance. They flower, which some gardeners may not want. Gumpos tend to have larger flowers than the Kurumes. The big disadvantages are the expense per plant which will be prohibitive for many gardeners and the difficulty in sourcing large enough runs of the same variety. Some will get thrip (particularly the Gumpo types) so choose the variety with care. Evergreen azaleas are much easier to strike from cutting than most rhododendrons so keen home gardeners with a long term view, may want to try building them up at home.

Camellia hedging options - C. brevistyla

Camellia hedging options - C. brevistyla

Camellia brevistyla

Camellia brevistyla

4) Camellias – some of the slow growing, small leafed varieties are suitable though the leaves will still be larger than buxus. They trim well, resprout from bare wood and are a good colour. There is a limited number suitable for keeping down to a metre, let alone 30cm, so varietal selection is important. Camellias are not easy to root from cutting for the home gardener and can be expensive to buy. Microphylla and brevistyla set seed freely so could be raised from seed at home if you can find a parent plant. Itty Bit is a true miniature for low hedges. Night Rider is very slow growing, though ultimately larger in size. You could keep it to a metre but it will be expensive to buy. We have opted to go the camellia route in the event of our moderate metreage of buxus hedging getting blighted and have raised seedlings of C. microphylla in the nursery for replacement.



5) Euonymus – there are assorted selections of small leafed euonymus being hailed as buxus replacements, including one named Emerald Gem. These look promising but international reports are that euonymus are somewhat disease prone and local reports are that it can be thrip-prone which will rule it out for shady areas. We would recommend trying this as hedging in a modest way before getting too carried away and we have yet to be convinced of its long term merit. It should be relatively easy to root cuttings and is sometimes available in a hedging grade at a reasonable price.

Melicytus obovatus

Melicytus obovatus

6) Our friend Tony is sold on Melicytus obovatus, a native from northwest Nelson which takes clipping very well. In the wild it will grow to 2 or 3 metres (but common buxus can become a huge shrub resembling a small tree left unclipped). Plantsman Terry Hatch at Joy Plants is very keen on this melicytus and produces it for sale. As far as we know, it has yet to be tested in the long term (by which we mean as a garden hedge past a decade) but it is worth a close look.

7) Selected pittosporums will make good taller hedges but you are fighting nature to keep them to the low level of edging buxus. Their leaves are also correspondingly larger. The compact pittosporums, Golf Ball and similar selections, make a quick option for clipping balls and topiary, if you don’t mind the paler shade of green. Keep them in full sun with plenty of air movement too.

8) Corokia will make a good hedge and there are dwarf selections available but they are harder to trim if the new growth is left to harden. If not cared for, they can develop bare patches.

Ilex crenata 'Helleri'

Ilex crenata 'Helleri'

9) Twining Valley Nurseries in Pokeno are producing Ilex crenata ‘Helleri’ as a buxus sub. Ilex are the holly family and crenata is a small leafed species from Japan and Korea. It is recognised as a good hedging plant but I have only seen it in photographs and I don’t know how low it can be kept. It is worth investigating.

New Zealand totara - a long term prospect for hedging

New Zealand totara - a long term prospect for hedging

10) Our native alpine totara, Podocarpus nivalis, stays very low and can be clipped hard to get dense foliage. However, it is a long term option, it will be expensive to buy in quantity and it does not have the good green of buxus.

We have yet to hear of low hedges which have stood the test of time – by which we mean 10 years, not one year. Until there are more reliable reports, we would not advocate spending too much money and effort on major plantings of alternatives. There simply are no easy answers for a replacement for buxus and we keep coming back to the view that it may be timely to review the role of low hedges in New Zealand garden design.

For earlier articles on the topic of buxus blight and the role of buxus in a garden situation, check out:
* The appropriately named buxus blight
* There is life beyond buxus hedging
* Trouble with buxus
* DEBBO (that is: death by bloody buxus overload)

The ilex again

The ilex again

There is life beyond buxus hedging

It is more about the lines and shapes, not the materials used.

Last week in Outdoor Classroom, I looked at some of the alternatives to buxus and came to the conclusion that there is nothing that really fits the bill when it comes to low growing hedges. And it is the low and slow Buxus suffruticosa that is the worst hit by the dreaded buxus blight and the hardest for which to find a suitable substitute. Sempervirens is the common buxus and it will make a large shrub or even small tree if you don’t clip it. Handy little suffruticosa is a dwarf form of sempervirens and the option that is commonly used when you want a little hedge around 30cm high.

Clipped hedges are essentially walls, usually green walls. Sometimes they are low walls, sometimes they are high walls but what they do is give some shape in a garden. The low, clipped box hedge is not about wind protection. It is largely about definition, formal lines and tidiness. The advent of buxus blight and the lack of an easy and cheap alternative to buxus may be a signal that it is time to look at alternative means of getting that definition. Maybe it is time to review the whole concept of tidy edgings and that is no bad thing where buxus hedging has become over-used and clichéd.

Tarting up the vegetable garden and turning it into a potager was all the rage coming up to twenty years ago and I, too, fell into the fashion trap. It took a lecture by garden historian, Helen Leach, to wake me up. She pointed out in no uncertain terms that it was completely impractical to vegetable garden surrounding by little buxus hedges. Vegetable gardens rely on constant cultivation of the ground and invading buxus roots make that impossible. Besides, the hedge provides nice, sheltered conditions for snails and slugs to set up residence and she is not wrong there. I got rid of the hedging I had inflicted on Mark and Felix and would suggest that gardeners worrying about the buxus hedging in their vegetable patch (potagers are so passé these days; the least you can do is refer to it as the kitchen garden) just rip it out and pretty up the area in other ways. Pavers, possibly used as stepping stones, are a great deal more practical to get defined lines. Raised beds can be used to define space if you want to go down that path. A spot of clipped topiary or matched vertical accents, even a pair of urns can give definition without compromising the prime purpose of the productive garden.

In the ornamental garden, it is a little different. Though after battling congested root systems to renovate mixed borders, I wouldn’t be wanting to use hedging as an edge- line for any gardens where I grow perennials or annuals which prefer not to compete for root space. Our preference is for more permanent materials which serve the same purpose without the maintenance and the problem of roots – in other words, low brick or stone walls about the height of a little buxus suffriticosa hedge, around 20 to 30cm. They take a bit to put in with poured footings and a mowing strip where laid beside lawn, but they are pleasingly permanent and they give the lineal definition that a low hedge also gives. Personally I prefer stone to brick, especially when it is a narrow, faced stone wall. I think it weathers better and looks wonderfully timeless without the slight garish aspect that even recycled brick can give but it is also the most expensive option in terms of time and requires a much higher level of skill to construct.
We have been laying a low brick edging this week to formalise a previously casual, rather wayward area. It is a situation where it would have been common for many to go in with a low buxus hedge but it all serves the same purpose – to channel the eye straight down to a longer view, to give definition and form to that particular border and to stop the birds from dispersing the soil and mulch as they scratch around. When we lay any concrete here, be it path or mowing strip, we tint it so that it does not dry out that stark white in the initial stages. Sometimes we will go to exposed aggregate also so the new area looks instantly weathered.

Concrete blocks laid and then plastered will serve the same function as brick or stone edging in getting the sharpest definition of line. If you are thinking to yourself that you like the softer effect of a hedge, that is what you achieve in the garden inside the edging where you can allow plants to froth over and blur the rigidity.

In less formal areas, edgings can be done with natural wood. At Te Popo Gardens near Stratford, Lorri Ellis has used the device of stacking narrow lengths of branch not much thicker than 10cm in diameter, all cut to the same length and laid with the cut end visible, modelled on a tidy wood pile. It creates a visual barrier in the same way as a hedge and Lorri has planted against it to soften the view. Even ponga logs can define an edge and last for years, ageing gracefully.

At Wisley in the United Kingdom, the long borders of classic herbaceous plantings are not edged in hedging to contain them. Instead big square pavers have been used. These guide the eye down the length of these parallel borders and protect the lawn because the exuberant plants just froth and flop on the pavers. If you are going to try the paver approach, experiment with different sizes. I suspect bigger is better unless your space is narrow.

You can edge with rows of some clumping perennial. Grasses are often used, though it is not to my personal taste. I think it looks a bit suburban in mondo grass or lirope but if we all liked the same thing, our gardens would all be very much the same.

In the end, it is not your buxus hedging that makes your garden look sharp and smart. It is the lines drawn with the hedging. So if buxus blight is forcing a re-think on you, maybe you don’t need another hedge at all. Having commented previously about the suffering from DEBBO (that is Death by Bloody Buxus Overload), I would welcome seeing some more creative and individual solutions to creating formal shapes and design in New Zealand gardens.

As a postscript to last week’s Outdoor Classroom, I would reiterate what I have said before about other forms of buxus. Overseas research says that while suffruticosa is the worst hit by buxus blight, followed by the other forms of sempervirens (which is very evident now in Taranaki), no buxus variety is resistant. So while anecdotally there are reports locally that the Japanese and Korean forms (microphylla, microphylla var. koreana and sinica) are not affected, this may be more related to individual conditions. I certainly would not be recommending spending much time or money on replacing affected hedges with Japanese or Korean buxus. The picture will be clearer in five years time but at the moment it appears you run the risk of replacing one infected hedge with another which will become infected in due course.